Cilacap - Indonesia made final preparations on Tuesday to execute eight foreigners by firing squad, as weeping family members paid last visits to their loved ones and ambulances carrying white coffins arrived at the drug convicts' prison.Relatives of Myuran Sukumaran and Andrew Chan, the Australian ringleaders of the so-called "Bali Nine" heroin trafficking group, arrived at Nusakambangan prison appealing for mercy for their loved ones, with Sukumaran's sister collapsing in grief.They are among nine prisoners, including nationals from Brazil, the Philippines, Nigeria and one Indonesian, facing imminent execution.Authorities in Indonesia have refused to disclose exactly when the executions will take place, but Sukumaran's mother Raji tearfully told reporters that her son would be put to death at midnight on Tuesday (17:00 GMT)."I am asking the government not to kill him. Call off the execution. Please don't take my son," she said.International condemnationJakarta says all the convicts will be executed at the same time. The executions were widely expected early on Wednesday after inmates were given formal notice on Saturday, after which authorities must wait a minimum of 72 hours.Executions are traditionally carried out just after midnight in Indonesia by a 12-man firing squad, with the condemned prisoner led to a clearing and tied to a post.President Joko Widodo, who believes Indonesia is facing an emergency due to rising drugs use, has signalled his determination to push on with the executions despite mounting international condemnation led by UN Secretary General Ban Ki-moon.Attorney-General Muhammad Prasetyo repeated the government's tough stance on Tuesday, telling reporters: "This is not a pleasant job, but it has to be done... to save this nation from drugs."Screaming for mercyEarlier on Tuesday, the families of Chan and Sukumaran, who have been visiting them frequently in recent days, were unable to control their emotions as they arrived at Cilacap, the town that serves as the gateway to Nusakambangan.As they were mobbed by a huge scrum of journalists, members of Sukumaran's family screamed and cried out "Mercy!" as they walked in a slow procession. His sister Brintha collapsed into the arms of family members.Chan, who like Sukumaran is in his 30s, married his Indonesian girlfriend in a jailhouse ceremony with family and friends on Nusakambangan on Monday, his final wish.When the families returned from Nusakambangan, Brintha broke down in tears at a press conference, telling reporters: "Please Mr. President Joko Widodo, I'm begging you, please -- please don't take my brother from me!"Andrew Chan's brother, Michael, added: "To walk out of there, and say goodbye for the last time, it's torture."The family of Filipina convict Mary Jane Veloso, who was convicted of trying to smuggle heroin into Indonesia but claims she was duped by international drug syndicates, also arrived in Cilacap en route to Nusakambangan to pay a final visit, racing past waiting reporters in a van.As they got out of the vehicle, Filipino priest Father Harold Toledano gave them each a blessing before they headed to the island. Among the group were Veloso's two sons, aged six and 12.'Evil man'Australia has mounted a vigorous campaign to save its citizens, who have been on death row for almost a decade.Foreign Minister Julie Bishop said on Monday the executions should be halted until a corruption investigation into judges who presided over the case is complete, but Widodo dismissed the request.Bishop on Tuesday criticised Indonesia's "chaotic" handling of the execution arrangements, saying there would be "consequences" if they went ahead."I think the ghastly process that the family have been put through today just underscores how chaotic this has been," she told the Australian Broadcasting Corporation."They do deserve respect and they do deserve to have dignity shown to them at this time of unspeakable grief. But that doesn't seem to have been extended to them at this time."In Sydney late on Tuesday about 300 supporters of the Australian pair held a vigil, with several people holding signs calling for the Indonesian president to show mercy.Veloso's case has attracted huge attention in her native Philippines, and President Benigno Aquino urged Widodo on the sidelines of a summit to grant her clemency, but Prasetyo insisted on Tuesday that the execution would go ahead.Protesters gathered outside the Indonesian embassy in Manila, where they have been holding regular candlelight vigils for Veloso, while there was also a rally urging clemency for the maid in Hong Kong, home to many Philippine domestic workers.At the Manila event, Sol Pillas, head of Philippine migrant workers' advocacy group Migrante, said Widodo "wants to portray himself as a strong leader but by executing an innocent woman, he will portray himself as an evil man".